Brevirhabdus pacifica gen. nov., sp. nov., isolated from deep-sea sediment in a hydrothermal vent field

A Gram-stain-negative, motile, aerobic bacterial strain, designated 22DY15^T, was isolated from a deep-sea sediment sample collected from a hydrothermal vent field located in the East Pacific Rise. The isolate was a short rod with a single flagellum and was positive for catalase and oxidase activities. Q-10 was the predominant respiratory quinone. The major polar lipids consisted of phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphoglycolipid, one aminolipid and three unidentified phospholipids. The principal fatty acid (>70%) was C-₁₈: iω7c. The genomic DNA G + C content was 64.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 22DY15^T represents a distinct lineage within the family Rhodobacteraceae. The closest relatives were species of the genera Aliiroseovarius (93.3-96.0% 16S rRNA gene sequence similarity), Sulfitobacter (94.0-96.0%) and Loktanella (92.0-95.9%). Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain 22DY15^T could be differentiated from its most closely related genera. Therefore, it is proposed that strain 22DY15^T represents a novel species in a new genus of the family Rhodobacteraceae, for which the name Brevirhabdus pacifca gen. nov., sp. nov. is proposed. The type strain of the type species is 22DY15^T(=JCM 19489^T=DSM 27767^T=CGMCC 1.12416^T=MCCC 1K00276^T).